Cast explosive charge.



.30 i quentfriction in the case `of the charge be- PATENT .-oEEIcE. l f

ERNST s oirotowsx'r, 0E HAMBEG, GERMANY, 'AssIGNoR 'ro E. I. De PoN'r DE NEMoUEs rowDEn coMPANY, y or WILMINGTON, DELAWARE, A coEronATIoN or NEW JERSEY. 1

Specification of Letters Patent.

cAs'r ExrLosIvE CHARGE.

Patented Feb.. 25, 1913.

onginaiapplicfation mea catetere', 1911, serial No. 652,480. Divided and this application inea May 15,

1912;A seriaINo. 697,588.

To all fav/tom t may concern: l Be itiknown that I, ERNST SoI'IoLowsxI, l:ti-subject vof the Empero-r of Germany, rel' siding at Hamburg,y Germany, have invent- 1 ed a new and useful Improvement in Cast Explosive-Charges, of which the following is a full, clear, and exact description, refer- .inceibeing had to the accompanying drawings, which. form a .part of this specification.

{The ordinary -cast fusible'explosive exhibits certain characteristics which lgive rise to. certain disadvantages which it is the object ofv my invention -to eliminate. One of characteristics is-the vlack of a homogeneous loading. Itf has been observed, on crosssection 'of cast explosive charges, that during the act of solidification small cavities orhllows aces are formed es eciallvalon` T p a p a the longitudinal central portion of the explosive charge, said hollow spaces arisingfrom the shrinkage of the fused mass in the process of chilling, which heretofore has been from the outer surface concentrically -to the inside. It '-is clear that in the moment of the firing, when the gases of the smokelessypowder impart the first impact to vthe projectile, the charge contained in the latter must undergo a l'Iind 'of crushing,

which will lead toy compression and conseingcompressible, .Ie. not having its highest attainable density before the shot is fired. Moreover the hitherto used explosive charges show very often 'a relatively coarse crystalline structure, owing, to the low cooling `of the fused mass, even if placed during solidification in cold Water. The long 'crys- -tals thus formed are liable to break in the moment of the violent impact; of the shot.

Hence premature detonations of the projectiles may and do occur, which destroy both y cannon and crew, and can only be avoided by eliminating friction within the shells. Furthermore, modern explosives 'are sometimes somewhat insensitive, and the det-onatio'n' of 'the primer is then not easily propagated-tothe whole'main charge, whereby the latter will often explode only partly. In order to offset this drawback, intermedi atecharges have been adopted, which act as propagators between the primer and the main cast explosive charge, but owing to the length of modern projectiles these inter1ne diate priming char es do not always perform their purpose, ecause they commonly surround the primer, thus being embedded In one end and too distant from the opposite end. of the long cylindrical main charge which will often remain partly unexploded, notwithstanding the use of the intermediate priming charge. I

The object of the present invention is to vproduce a cast fusible explosive charge in which the coarse crystalline structure above mentioned is absent and which instead exhibits an absolutely homogeneous fine crystalline structure' of high density and devoid of hollow spaces and which cannot be further compressed bythe impact of the shot, thereby avoiding both premature detonation and only partial explosion of the charge.

The invention consists of an explosive charge comprising'a main body of explosive -and an internal longitudinally extendingl explosive core tightly and permanentlyvsurrounded by the Ina-in body of the explosive.

In order that the invention may be fully I understood, I will irst describe thel method which I have adoptedfor the manufacture of the charge.

Into the centerline of the mold a cold substance made of an explosive inthe shape of a rod is introduced and maintained in position by means of a suitable appliance from its upper end. The'introduct-ion of the cold rod made of anl explosive substance can be efected in such manner that this rod 1s `introduced into thefempty mold before the fused material is poured into same, or the rod can be inserted after the casthas been made by pressingsame into the latter. The

filling of the mold'v may be carried out in accordance with any desired pouring process, for instance, by means of an ordinary casting, by means of casting under pressure, or by means of a heatable pouring funnel. In the latter case the neck ofthe funnel can be used for the guiding of the cold rodshaped substance. The latter consists, for `instance, of an explosive which is not covered and which has been `fused and chilled, or of an explosive pressed'in a tube-shaped closed shell, the latter, for instance, consisting of Celluloid, pasteboard or sheet metal. The diameter of this cold, rod-shaped explosive material is to be adapted'to the diameter of the explosive charge. By means of providing this cold rod made of an explosive substance in the center of the cast, or 'by sinking this rod into the fused explosive mass, a quick chilling of the liquid portion l of the charge is effected. The rod-shaped cold explosive body is thus t-ightly surrounded by the chilling explosive charge. Experience shows that fusing of the rod substance does not take place, or takes place to but a slight extent, Whenever the casting operation is carried out at ailow a. casting temperature as possible and, with indicationsof the commencement of the formation of` crystals. This condition is of great importance in this method of casting and for the purpose of producing the high density of the cast obtained thereby.4

Then using a rod made of a pressed explosive in a pasteboard or other cover, this pressed explosive serves directly as a priming charge, which tightly 'bears against the bottom of the explosivev charge container surrounding the igniting charge of the fuse. Owing to the long shape of vthis priming charge passing almost throughout the entire length of the charge, the detonation becomes very-satisfactory, and a very strong propa-v 30 gation of the ldetonation upon the fuse main charge is more fully insured tnan in the case of the vusual priming charges placed with one side only near the 'fuse and surrounding the same. Of special importance is the advantage that, as'a consequence of the quick cooling of the cast simultaneously fromv the outside and from the inside, a very ne crystallinestructure of the cast, and as high a density as' possible, are. obtained. For this reason large crystals willnot break, even thcugh theimpact of the shot should be especiallyrviolent, and theA charge will not contract, since the highest -possible density has been imparted tofthefs'ame during the casting, and since a densifying beyond this point is not possible. These two points render impossible movements Within the explosive 'charge with a violent'impact o f the shot, thus directlyy insuring against premature detonations to an extent which lis not obtained when using other pouring methods. Of special importance is the fact that the explosive used for the coldrod-shaped bod 'can possess chemical properties entirely di ferent fromthose of the main charge. It is therefore possible to use, for the rod charge, for instance a brisant explosive which detonates with violence; While for the main charge'a more inert fused explosive which is very safe against shock, for instance trinitrotoluol, can begused.

Explosive charges embodying m invention, prepared in accordance with t e above described method, when cut open, clearly 65 show that they have been actually so pretherein.

, the explosive charge forming the subject pared, which guarantees to a hi h degree the good quality of the char e. W en using,

' for instance, the rod-shape body without a cover and made of a fused explosive, the structure of the same cany be clearl vdistinguished from that of the 4main c ar e, since its appearance is diiferent, notwit standing the fact that an exceedinglyintimate fusion of the two charges has been effected.v This is, of course," still more apparent when the rod body is used in a pressed state and with a special cover.

In the drawings, Figures 1 and 2 are longitudinal sectional Vviews of molds containing alternate forms of explosive charges embodying my invention, Fig. 1 showing an uncovered explosive core and Fig. 2 an'. explosive core in a shell.

a represents an iron castin mold, -b a' paste-board container placed 1n the same and c (F ig. 1) a rod-shaped body offus explosive extending vthroughout the axial length of the mold.

d (Fig. 2) represents a rod-'shaped body consisting of a paste board shell d with several pressed bodies of explosives, c', placed e represents the main explosive body. I do not herein claim the process by which matter of this application is manufactured, as the same :forms the subject mat-ter of an application heretofore filed `by me, Serial No. 652,480, led October 3, 1911, of which this application is a division.

I am aware that it"` has been proposed to 4 make the; explosive char es of pro'ectiles-V less liable to premature etonation ollow-V ing internal friction by surrounding a central core of dynamite or other more sensi-A tive explosive covered by absorbent material with a body of nitro-gelatin or other vless sensitive explosive similarly covered;

also to divide t-he loose main explosive charge into a number of sections sup orted 11g by shells, disks, webs, etc.; also to ma e theI bursting charge' of layers of dynamite cloth. But these .charges are more or less com` pressible so that the dangerof internal friction in the movement ofl the shot is not altogether removed. In my invention, however, all danger of internal friction is re- 'moved by imparting to the explosive charge the highest attainable densit so that it cannot be further compressed y the shock of the projectile when the shot is red or the target hit. Anotherimportant factor is the fine crystalline structure 4.of .the charge, which can be produced only by the process described'in the application of which this v125 is a division. y l

. Having now fully described my` invention,

what I claim and desire to protect by Letters Patent' is: f

1. A cast explosive comprising a main 1 30 l body-of a relatively dense and 'iine crystalliieex'plosive in the form of -a solid block surrounding a longitudinally extending cenl, tml oore of a less dense and previously 5 'eiiilled explosive and therefore adapted during the casting to help control the crystalv `linestructure and density of the main body.

, .2. A cast explosive comprising a main explosive body consist-ing of a solid block and 6' 2mv internal uncovered explosive core di rectly and integrally united with the mainv ybody.

ERNST SOKOLOWSKI.

VVit-nesses ERNEST H. L. MUMMENHOFF, IDA CHRIST HAFERMANN. 

